How Landsat Helps Michigan: Invasive Reeds, Shifting Coasts, Algae and a Dam Disaster

Water means a lot to Michigan, the Great Lakes State. Its name comes from an Ojibwe word meaning large or great water or lake. The only state touching four of the five Great Lakes — Michigan, Superior, Huron and Erie — it has the longest freshwater coastline in the United States. But it also has forests, farms, mines, cities and even sand dunes, and much of what happens on land connects to its inland and coastal waters.

From hundreds of miles up, Landsat satellites show those connections between land, water, people and wildlife — especially for the Great Lakes Restoration Initiative (GLRI), in which federal agencies and partners, including neighboring states, work to protect and restore the lakes.

Controlling an invasive reed

Preventing and controlling invasive species — plants, fish, mussels — is a GLRI focus. Landsat has helped map the dense, towering invasive Phragmites australis, or common reed, along southeastern Michigan's coast — Saginaw Bay, Lake St. Clair and Lake Erie. Unchecked, it crowds out habitat for fish, plants and wildlife, gets in the way of recreation, and can be a fire hazard. Maps help state and local authorities manage it.

Tracking coastal change

Landsat data underpin NOAA's Coastal Change Analysis Program, which maps coastal land cover and change. The Michigan Coastal Management Program works with NOAA to protect the coast, and with GLRI support the program uses decades of Landsat data to track changes — such as new development — that lead to gains or losses of wetlands, forest, grass and pavement. That guides wetland restoration and other decisions.

Watching for algae

A GLRI goal is "reducing nutrient runoff that contributes to harmful/nuisance algal blooms." Landsat has helped map toxic algal blooms and the nuisance alga Cladophora, which breaks off underwater rocks or invasive mussels and washes ashore as green muck.

Landsat data on forest canopy change also helped Forest Service scientists study the watersheds of Lakes Superior and Michigan and predict rising phosphorus — which feeds algae — in streams flowing into them, so the Forest Service could target resources to improve near-shore water quality.

Showing a disaster

When the Edenville and Sanford Dams failed on May 19, 2020, amid flooding on the Tittabawassee River in central Michigan, Landsat 8 captured the aftermath the next day. News outlets set that image beside one from the year before to show the flood's toll on land and neighborhoods. USGS EROS's Image of the Week highlights other events seen by Landsat.

The Midland area and the upstream Edenville and Sanford Dams, June 3, 2019, and May 20, 2020, after the dams failed in heavy rain on May 19. Joshua Stevens, NASA Earth Observatory, and USGS

Landsat: national infrastructure

The USGS National Land Imaging Program supplies satellite imagery and geospatial data to government, business, universities and the public, with worldwide access to Landsat through the USGS Earth Resources Observation and Science (EROS) Center.

• Landsat is the most widely used land remote-sensing source in federal civilian agencies, informing everyday decisions that protect life and property, safeguard the environment, advance science and education, support climate resilience and grow the economy.
• Businesses build it into logistics, resource and investment tools; commercial imaging firms use it to refine their products.
• A 2017 USGS study put its annual economic benefit to the U.S. at $2.06 billion — far more than it costs.
• Landsat 8 and 9 cover Earth's land every 8 days; NASA and the USGS are reviewing studies for Landsat Next.
• Its long, consistent record and no-cost data policy let users study large areas and long-term change.

Sources

Based on U.S. Geological Survey, "Michigan and Landsat," Fact Sheet 2021–3047, USGS; a work of the United States government in the public domain. It cites Naranjo (2017), NOAA (2014), GLRI (2021), Ramsayer (2014), Brooks and others (2015), the USDA Forest Service Northern Research Center (2014), Patel (2020) and Straub and others (2019).